New technology makes semi-solid aluminum alloy easier to form

Recently, it was learned that the Advanced Controlled Solidification team of the National Non-ferrous Metals Composite Engineering and Technology Research Center of Beijing Nonferrous Metal Research Institute mastered the basic principles of semi-solid metal solidification under the continuous support of the National 973, 863 Program and international cooperation projects. Invented a new technology of helical ring seam electromagnetic stirring, and solved the core technical problems of semi-solid aluminum alloy forming.

To make a metal material into a desired part, there is a process from melting to forming, and there is also a transition from liquid metal to solid metal. In the 1970s, it was discovered that metal materials cooled from the liquid state to the solid state. The first solid part solidified out of the liquid and there was a semi-liquid, semi-solid coexistence transition state. This liquid-solid coexisting metal was called Semi-solid metal.

Xu Jun, chief expert and professor-level senior engineer of the Beijing Nonferrous Metals Research Institute, said that semi-solid metal forming technology can theoretically be applied to most metals such as aluminum, magnesium, copper, steel, and metal matrix composites, but Due to the different nature of various metal alloys, different difficulties are encountered in the preparation of semi-solid metal slurries. In spite of this, the technology is continuously being applied as a green, near-finishing new technology.

Using this method, a high-strength aluminum alloy cast rod with a diameter of more than 300mm can be prepared. At the same time, this technology has settled into Hunan Wenchang Technology Co., Ltd. and has become the first domestic semi-solid specialized production enterprise for wear-resistant aluminum alloy parts for vehicles. It has replaced imports and realized the transformation of scientific and technological achievements into practical productivity.

At present, the technical team is using this technical principle to develop aluminum-based composite brake brake discs for subways and motor vehicles. Currently, this product can only be produced in Germany and Japan. After the research, the product has passed the assessment test of the China Academy of Railway Sciences. It is expected that China's subways and trains will be equipped with brake discs, a key component of domestic production.